Modifying an LS 5.3 Head for Towing

[turbo camino]

The stock tune has to be modified using HP Tuners or EFI Live. I don't know of any handheld 'tuners' that allow the kind of detail needed to do it correctly, last one I used you could only select pre-defined 'tunes' from a list and see which one you liked. That is not what you need, this isn't a '87 TBI. Not to mention the handheld 'tuners' cost about the same as a full-featured tuning suite.

Buy HP Tuners. Plug in to the truck and read the stock tune. Open the tune file, make adjustments, write file, drive and datalog. Take fuel trim data from log and paste into MAF or VVE to make fueling corrections. Save changes, write truck, drive & log. Repeat until satisfied.

Or, find a tuner in your area and have them do it.

[turbo camino]

Anyone can download the HP Tuners software and install it in demo mode. --> https://www.hptuners.com/downloads/

Here's a stock sample file from a '07 4.8 Silverado:

2007 Silverado 1GCEC14C67Z531863 E38-T42 4L60E 1191450240.zip

It is NOT a .zip file; change the extension to .hpt

Open it in the VCM Editor and look around, see if it's something you feel like tackling. It's a steep climb to start out on an E38.

[gmrocket]

You’re funny...

You made it sound so simple....now it’s not.

If I paid you to do this “simple” fix to improve the trucks towing at highway speeds, what would you charge?

I can’t even download that because it’s massive...so now what?

I’m challenged with this stuff, you are the expert...I’m not here to learn this stuff because I have zero interest in it..I want you to guide me.

Seems like I see and hear all kinds of claims by tuners and efi experts on how it’s just so simple to improve something like this, yet it never is

[turbo camino]

Oh man, I am NOT an expert, not at all. I am just a DIYer tinkering with his own truck which has a much simpler ECM than a E38. Though it had the same problems with the tune as all the LS-powered trucks so I know basically what needs to be addressed. I wouldn't know up from down if I had to do VVE on a E38. I know enough about it to know I don't know enough about it.

A real professional tuning shop who does that platform regularly could get it done in an hour or less, I'd imagine. I'm not talking a dyno tune or anything, just they'd already know where all the low hanging fruit was. There are lots of places that do 'mail order tunes' but you have to have your own HPT interface. They send you a file and you flash it. If you don't want to even download the software I don't see that happening.

[MT Jeff]

How do you find said tuners? I have a Tahoe I'd like to do a 6.0 swap with a small cam. Not much else. Just more power everywhere. Not a race car just more power. Do places link HP tuners have locator links.

[turbo camino]

HPT doesn't maintain a list/locator, but you can post in the forum with 'looking for a GM tuner near [insert place here]' and usually someone will speak up.

As much as I hate facebook, that's probably where you should start though. That's where everything that used to be in your local Yellow Pages has migrated to. Sadly.

[Truckedup]

I had an 03 Silverado shortbed 2wd 5 speed manual, 3.42 gears,4.8 , 4200 pounds on the scale. It would tow 2500 pounds ok so long as the engine was at 4000 rpm going up moderate grades. I have a 09 Ranger 4.0 4x4 5 speed manual , 3.73 gears, about 3750 pounds. I think it makes more low speed power than the 4.8 LS...

[77cruiser]

I have an 04 Duramax fore sale, that would be easier.